<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>

        /* 选择器嵌套的越深，权重越高 */
    #one{

        color: red;
    }
    body>div>p{
        
    }
    
    </style>
</head>
<body>
    <div>


        <p id="one">hello world</p>
    </div>
</body>
</html>